Rotary engine or pump



2 mis-shan 1 V6' E. ERICSSON RUIM -HGIHE 0R mi Film 1p1-i1 4, 1942 Nov. 30 1943.

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wrm: mm: on rma l Filed Aprii 4. 1942 2 sheets-sheet 2 Z fifi/ez;

Patented Nov. 30, 1943 UNITED STATES PATENT lOFFICE 5 Claims.

This invention relates to an engine or pump of the type having a chamber of substantially toric form in which a piston revolves and also having a cut-off disk which divides the chamber into segments of different lengths. The construction of such machines involves the diflicult problems of preventing leakage past the piston and sealing the chamber in which the piston operates both along the peripheral slot in the tore where the piston connection with the rotor moves and around the intersection of the cut-off disk with the tore, while minimizing losses due to friction.

The principal object of the present invention is to provide novel and efficient means for reducing leakage and friction around the piston and between the chamber wall and cut-off disk of a machine of the class described.

With this object in view, I have found that friction may be reduced by the tangential arrangement of the cut-off disk relative to the rotor which is described and claimed in my Patent No. 1,689,523, granted October 3G, 1928, but that the sealing devices at the junction of the cut-off disk and chamber walls and expansible ring embracing the piston described in said patent, may be improved upon by positively guiding the piston ring so that it cannot strike or cause excessive wear upon the disk sealing ring. In my construction at least one sealing ring is provided to embrace the toric chamber and is held in resilient contact with the high pressure face of the cut-off disk. This ring is split and has its ends tted against opposite faces of the rotor at points spaced apart along the line of contact between the rotor and disk. Unless prevented from doing so, each piston ring normally expands and strikes the ends of such disk sealing ring as the piston reaches a point in its cycle where it is moving substantially parallel to the disk in the shorter segment of the toric chamber. According to the present invention, I insure proper clearance between the rings at this critical point by slight offsetting cr increasing of the curvature of a segment of the toric chamber.

Referring to the accompanying drawings which illustrate a preferred form of my invention:

Figure 1 is a central vertical section through an engine embodying my invention, the section being taken in the plane which includes the axes of the main and disk shafts;

Fig. 2 is a vertical section through the disk taken at right angles to the section shown in Fig. l;

Fig. 3 illustrates diagrammatically my improved form of piston. ring guide segment, the

modication of the tore being greatly exaggerated for clearness;

Fig. 4 is a plan view showing the cut-off disk and lower part of the casing therefor, together with the disk sealing ring;

Fig. 5 is a section taken approximately on the line 5--5 of Fig. 2, with the rotor removed, and

Fig. 6 is a partial section taken approximately on the line 5 6 of Fig. l and partial side elevation showing the rotor, piston and a portion of the upper part of the casing.

Referring to the drawings, the numeral B indicates a machine base which is provided with suitable bearings for a main shaft 9 and a disksupporting shaft I0. These shafts are disposed at right angles to each other with their axes extending in a common vertical plane. Fixed on the shaft 9 is a rotor II formed with a relatively thin peripheral flange I2 upon which a piston I3 is rigidly mounted. A chamber I4 of tore shape is provided to revolubly receive thev piston Intersecting the chamber I4 and dividing it into unequal segments is a large disk I5 which is keyed to the shaft IG. This disk has its upper face disposed tangentially to the inner periphery of the chamber I4 and outer periphery of the flange I2. The radius of the circle of contact between the disk I5 and flange I2 in the plane of the disk is substantially equal to the radius of the periphery of said flange and the shafts 9 and IEI are connected together for operation at the same speed by beveled gears IG. By this arrangement the outer periphery of the flange I2 is caused to make rolling contact with the face of the disk I5 and friction between these moving parts is minimized. The disk I5 is enclosed in a suitable casing and is formed with a heavy peripheral flange I1 which is supported by an antifriction wheel I3 mounted on a casing I9 beneath the disk casing.

An opening 2i! (Fig. 4) is formed in the disk I5v to allow the piston I3 to pass through it to and from a relatively short, guide segment 2I of the toric chamber below the disk. As further shown in Figs. 3, 4 and 6, I provide a sealing ring 22 which is resiliently pressed against the face of the disk I5 by a multiplicity of small coiled springs 23 mounted in recesses in the chamber walls. This ring embraces the high pressure end 24 of the longer or power segment of the chamber I4. The intersection of the low pressure or exhaust end 25 of the same segment with the disk is indicated in dotted lines in Fig. 4 and in full lines-inFig. 5. The ring'22 is substantially elptical in plan view and has ends 2t which are spaced apart only sufciently to allow the flange I2 to pass between them. The entire bottom face of the ring 22 which extends to the point of contact with flange I2 must be smoothly finished to minimize friction and it must also make rm and continuous, sliding contact with the disk to prevent serious leakage or loss of compression.

The piston I3 is provided with one or more split, resilient rings, such as the ring 21, which normally expands so that it slidably fits the toric surface of the chamber I4 to prevent leakage of fluid past the piston. To avoid interference between the ring 21 and ends 25 of the ring 22, I so modify the curve of the segment 2! as to guide the ring 21 outward past the ends 25 of the ring Y Y 22. This may be accomplished, as indicated in Fig. 3, by making the radius A of the segment 2| somewhat shorter than the radius B of the main chamber I4 and by locating the center C for the radius A substantially below or outward from the center D for radius B. It is further desirable that the ends E- of the arc of radius A shall meet the arc F of radius B where both arcs intersect the lower disk surface. Thus the segment 2i is formed to merge smoothly into the main chamber segment at both ends. For the sake of clarity, the curvature of arc 2i, as shown in Fig. 3, is greatly exaggerated. It has been found that outward movement of the ring 21 relative to the sealing face of the ring 22 amounting to a few thousandths of an inch in the plane bisecting the segment is sufficient. The amplitude of this movement, which is indicated by the dimension G in Fig. 3, o-rdinarily will not substantially exceed .O1 of an inch and in some cases it may be as small as .005 of an inch. The periphery of the piston body has suiiicient clearance relative to the walls of both chamber segments to allow the piston to revolve freely within these segments from its xed position on the rotor. To seal the annular slot in the walls of the chamber I 4 at both faces of the annular flange I2 of the rotor II, I provide series of rings 3S which extend circumferentially of the rotor and are spring-pressed against opposite faces of the flange respectively, as shown in Fig. 1, and more fully described in my Patent No. 1,689,523.

My invention may be embodied in an engine, motor or pump by suitable modication of the connections for supplying uid to the toric chamber. Connections for propelling the piston by steam are illustrated. For this purpose a cylindrcal steam chest 2t is shown above the. disk I5 and a rotary valve 29 is mounted in the chest and connected to the shaft it. Steam under pressure is admitted to the chest 23 by a pipe 36 (Fig. 5) and a pipe 32 connects the chest to an inlet port 3i communicating with the high pressure end of the main or power segment of the chamber I4. To exhaust steam from the low pressure end of the power segment, I provide a port 33 communicating with an exhaust pipe 34. The rotary valve 2&3 is formed with a port 35 (Fig. l) adapted to allow the passage of steam from the chest to the pipe 32 during a controlled portion of the cycle of operation.

In operation, assuming that the piston has just passed through the opening 2&3 in the disk I5 in the direction indicated by an arrow in Fig. 6, this disk now completely separates the guide segment 2I from the power segment 'I4 and as the piston continues to move'it uncovers the steam inlet port 3I and steam under pressure is admitted behind the piston by the Valve 29 in the chest 23. The resulting fluid pressure forces the piston through the main segment of the chamber I4, thereby rotating the rotor I I, shafts 9 and I0 and disk I5. The supply of steam is shut olf at a suitable point in the cycle and after further expansion of the steam in the chamber I4, the piston passes the exhaust port 33 through which the expanded steam is exhausted. At this instant the opening 29 in the disk I5 has been moved into registry with the low pressure end of the main chamber segment and the piston passes through the opening into the guide segment 2I of the chamber. As the piston continues toward the central point in segment 2I, the piston ring 21 is moved downward so that as it expands in the opening 20 it cannot engage the ends of the ring 22. Thus the ring 21 is forced radially outward, a few thousandths of an inch and then is guided back to its normal position on the piston as the latter passes upward through the disk opening 2i? into the main chamber segment. The disk I5 immediately closes across the end 24 of this segment, thereby completing the cycle of operation. It will be understood that my increased curvature of the segment 2i is not great enough to require a departure of the piston body from its true toric path about the axis of the main shaft 9.

Having described my invention, what I claim as new and desire to protect by Letters Patent is:

l. In a machine of the class described, a rotor, a piston mounted on the rotor, an annular chamber formed to receive said piston, a resiliently expansible ring embracing the piston for sliding contact with the chamber walls, a disk extending tangentially to the rotor and dividing the chamber into normally separate segments of unequal length and means operatively connecting the disk to the rotor, the disk being formed with an opening through which the piston is adapted to pass from one of said segments into the other and the shorter of the segments being formed to shift said ring radially outward relative to the rotor and away from an end of the longer chamber segment.

2. In a machine of th'e class described, a rotor, a piston mounted on the rotor, an annular chamber formed to receive said piston, a resiliently expansible ring embracing the piston for sliding contact with the chamber walls, a disk extending tangentiallyV to the rotor and dividing the chamber into normally separate segments of unequal length and means operatively connecting the disk to the rotor, the disk being formed with an opening through which the piston is adapted to pass from one of said segments into the other and the shorter of the segments being formed with' slightly increased curvature to oscillate said ring radially outward relative to the rotor and away from an end of the longer chamber segment.

3. In a machine of the class described, a rotor, a piston mounted on the rotor, an annular chamber formed to receive said piston, a. resiliently expansible piston ring embracing the piston and arranged to make sealing contact with the chamber walls, a disk extending tangentially to the rotor and dividing the chamber into normally separate segments of unequal length, means operatively connecting the disk to the rotor, the disk being formed with an opening through which the piston is adapted to pass from one of said segments into the other and a sealing ring resiliently engaging the face of said disk andA embracing said chamber at its intersection with the disk, the sealing ring having ends engaging opposite faces of the rotor at its periphery in contact with the disk and the shorter of the segments being formed to oscillate the piston ring radially outward relative to the rotor to thereby avoid Contact of the piston ring with th'e sealing ring.

4. In a machine of the class described, a rotor, a piston mounted on the rotor, an annular chamber formed to receive said piston and having an annular slot containing the outer periphery of the rotor, a resiliently expansible piston ring embracing the piston for sealing contact with the chamber walls, a disk mounted for rolling Contact with the periphery of the rotor and dividing the chamber into segments of unequal length, means operatively connecting the disk to the rotor, th'e disk being formed with an opening through which the piston is adapted to pass from one of said segments into the other and sealing means resiliently engaging the face of said disk and embracing the longer segment of said chamber at one of its intersections with the disk, said sealing means extending to the line of rolling contact between the rotor and disk and means for oscillating the piston ring radially outward relative to the rotor during the movement of the piston within the shorter of said segments to thereby avoid contact of the piston ring with said sealing means.

5. In a machine of the class described, a rotor, a piston mounted on the rotor, an annular chamber formed to receive said piston, a resiliently expansible piston ring embracing the piston for sealing contacct with the chamber walls, a disk mounted to extend in rolling contact with the periphery of the rotor and dividing the chamber into normally separate segments of unequal length, the longer of said segments constituting a working chamber and the shorter segment constituting a guide for the piston ring, means operatively connecting the disk to the rotor, the disk being formed with an opening through which the piston is adapted to pass from one of said segments into the other and a sealing ring resiliently engaging the face of said disk and embracing one end of the longer segment at its intersection with the disk, the sealing ring extending to the line of contact between the periphery of the rotor and disk and the shorter of the segments being formed to oscillate the piston ring radially outward relative to the rotor to thereby prevent interference between the piston ring and sealing ring at said line of contact.

ELOV ERICSSON. 

